Image sensors and methods of forming image sensors

ABSTRACT

Image sensors are provided. An image sensor includes a color filter layer. The image sensor includes a metal structure adjacent a sidewall of the color filter layer. The image sensor includes an insulating layer on the color filter layer. Moreover, the image sensor includes an electrode layer on the insulating layer. Methods of forming image sensors are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation application of and claimspriority from U.S. application Ser. No. 16/266,531, filed Feb. 4, 2019,which is a continuation application of and claims priority from U.S.application Ser. No. 15/350,201, now U.S. Pat. No. 10,243,022, filedNov. 14, 2016, which claims the benefit of Korean Patent Application No.10-2015-0179205, filed Dec. 15, 2015, in the Korean IntellectualProperty Office, the disclosures of which are hereby incorporated hereinby reference in entirety.

BACKGROUND

The present disclosure relates to image sensors. Image sensors that takeand convert images into electrical signals are used not only inelectronic devices for general consumers such as a digital camera, acamera for a cellular phone, and a portable camcorder, but also incameras mounted in an automobile, a security system, and a robot. It maybe beneficial for an image sensor that includes a photodiode to provideminiaturization and high resolution.

SUMMARY

Provided are methods and image sensors using an organic photoelectriclayer.

According to some embodiments of present inventive concepts, an imagesensor may include a semiconductor substrate including a photoelectrictransducer. The image sensor may include a color filter layer on thesemiconductor substrate. The image sensor may include a metal structureon the semiconductor substrate and adjacent a sidewall of the colorfilter layer. The image sensor may include an insulating layer on thecolor filter layer. Moreover, the image sensor may include a transparentelectrode layer on the insulating layer and connected to the metalstructure through an opening of the insulating layer.

In some embodiments, the image sensor may include a transparent layer onthe color filter layer. The insulating layer may be between respectiveportions of the transparent layer and the transparent electrode layer.Moreover, the respective portion of the transparent layer may be a firstportion, and the transparent electrode layer may contact a secondportion of the transparent layer through the opening of the insulatinglayer.

According to some embodiments, the image sensor may include an organicphotoelectric layer on the transparent electrode layer. The insulatinglayer may include a protruding portion thereof that protrudes toward theorganic photoelectric layer. The protruding portion of the insulatinglayer may include an uppermost surface that is coplanar with anuppermost surface of the transparent electrode layer. Moreover, theprotruding portion of the insulating layer may overlap the color filterlayer.

In some embodiments, the metal structure may include a tungsten portionand an aluminum portion on the tungsten portion. The transparentelectrode layer may contact the aluminum portion. Moreover, sidewalls ofthe aluminum portion of the metal structure may be tapered toward thetransparent electrode layer.

According to some embodiments, the metal structure may include tungstenthat contacts the transparent electrode layer. Additionally oralternatively, the insulating layer may extend onto a portion of themetal structure, and a first width of the metal structure may be widerthan a second width of the opening through which the transparentelectrode layer connects to the metal structure.

In some embodiments, the image sensor may include a metal contact in thesemiconductor substrate. The metal structure may contact the metalcontact and may include different first and second metallic materials.The first metallic material may contact the metal contact. Moreover, thesecond metallic material may be on the first metallic material, maycontact the transparent electrode layer, and may be wider than the firstmetallic material.

According to some embodiments, the second metallic material may be onopposing first and second sidewalls of the first metallic material. Themetal contact and/or the metal structure may include a tapered width.

In some embodiments, the color filter layer and the photoelectrictransducer may include a first color filter layer and a firstphotoelectric transducer, respectively. Moreover, the image sensor mayinclude a second color filter layer on a second photoelectrictransducer. The metal structure may be between the first and secondcolor filter layers. The image sensor may include a transparent organiclayer between the first color filter layer and a first portion of theinsulating layer and between the second color filter layer and a secondportion of the insulating layer.

According to some embodiments, a surface of the transparent organiclayer may be coplanar with a surface of the metal structure thatcontacts the transparent electrode layer. Additionally or alternatively,the image sensor may include an organic photoelectric layer on thetransparent electrode layer. The second portion of the insulating layermay include a protruding portion thereof that protrudes toward theorganic photoelectric layer and isolates a first portion of thetransparent electrode layer that is on the first color filter layer froma second portion of the transparent electrode layer that is on thesecond color filter layer.

In some embodiments, the transparent electrode layer may contact aportion of the transparent organic layer through the opening of theinsulating layer. Additionally or alternatively, the insulating layermay overlap opposing first and second sidewalls of the metal structure.

An image sensor, according to some embodiments, may include a colorfilter layer. The image sensor may include a metal structure adjacent asidewall of the color filter layer. The image sensor may include atransparent layer on the color filter layer. The image sensor mayinclude an insulating layer on the transparent layer. Moreover, theimage sensor may include an electrode layer on the insulating layer. Theinsulating layer may be between respective portions of the transparentlayer and the electrode layer.

In some embodiments, the image sensor may include an organicphotoelectric layer on the electrode layer. The insulating layer may beon a portion of the metal structure. The electrode layer may beconnected to the metal structure through an opening of the insulatinglayer. Moreover, a first width of the metal structure may be wider thana second width of the opening through which the electrode layer connectsto the metal structure.

An image sensor, according to some embodiments, may include first andsecond color filter layers. The image sensor may include a metalstructure between respective sidewalls of the first and second colorfilter layers. The image sensor may include an insulating layer on thefirst and second color filter layers. The image sensor may include anelectrode layer on the insulating layer. Moreover, the image sensor mayinclude an organic photoelectric layer on the electrode layer. Theinsulating layer may include a protruding portion thereof that protrudestoward the organic photoelectric layer.

In some embodiments, the image sensor may include a transparent organiclayer between the first color filter layer and the insulating layer andbetween the second color filter layer and the insulating layer. Theinsulating layer may be on a portion of the metal structure. Theprotruding portion of the insulating layer may isolate a first portionof the electrode layer that is on the first color filter layer from asecond portion of the electrode layer that is on the second color filterlayer. The electrode layer may be connected to the metal structurethrough an opening of the insulating layer. A first width of the metalstructure may be wider than a second width of the opening through whichthe electrode layer connects to the metal structure. Moreover, acontinuous portion of the electrode layer may contact the organicphotoelectric layer, a sidewall of the protruding portion of theinsulating layer, and the metal structure.

A method of forming an image sensor, according to some embodiments, mayinclude forming an insulating layer on a color filter layer. The methodmay include etching the insulating layer to form an opening that atleast partially exposes a metal structure that is adjacent a sidewall ofthe color filter layer. Moreover, the method may include forming anelectrode layer in the opening of the insulating layer.

In some embodiments, the method may include, before forming theinsulating layer, forming a transparent layer on the color filter layer.Additionally or alternatively, forming the electrode layer may includesimultaneously forming an electrode material in the opening of theinsulating layer and on a portion of the insulating layer that isoutside of the opening. Moreover, forming the electrode layer mayinclude forming the electrode layer to contact a portion of thetransparent layer through the opening. Additionally or alternatively,forming the transparent layer on the color filter layer may includeforming the transparent layer on a red first color filter layer and ablue second color filter layer. Forming the insulating layer may includeforming an oxide layer on the transparent layer. Forming the electrodelayer may include forming an indium tin oxide (ITO) layer on the oxidelayer and on the metal structure.

According to some embodiments, the method may include forming aphotoresist material on a portion of the insulating layer, andperforming an etch of the insulating layer while the photoresistmaterial is on the portion of the insulating layer. Performing the etchof the insulating layer while the photoresist material is on the portionof the insulating layer may include performing a first etch of theinsulating layer. The method may include performing a second etch of theinsulating layer to form a recess that overlaps the metal structure,without exposing the metal structure. Etching the insulating layer toform the opening that at least partially exposes the metal structure mayinclude performing a third etch of the insulating layer.

In some embodiments, the photoresist material may be a first photoresistlayer. The method may include removing the first photoresist layer andforming a second photoresist layer on the insulating layer, beforeperforming the second etch of the insulating layer. Moreover the methodmay include removing the second photoresist layer, before performing thethird etch that forms the opening that at least partially exposes themetal structure.

According to some embodiments, performing the etch may include forming aprotruding portion of the insulating layer. Moreover, forming theelectrode layer may include forming the electrode layer on theprotruding portion of the insulating layer.

In some embodiments, forming the electrode layer may include depositingan electrode material on the insulating layer, and performing a chemicalmechanical polishing (CMP) process on the electrode material until aportion of the insulating layer is exposed. The portion of theinsulating layer that is exposed by the CMP process may overlap thecolor filter layer. Moreover, the method may include forming an organicphotoelectric layer on the electrode layer and on the portion of theinsulating layer that is exposed by the CMP process.

A method of forming an image sensor, according to some embodiments, mayinclude forming a transparent layer on a color filter layer. The methodmay include forming an insulating layer on the transparent layer. Themethod may include forming an electrode layer on the insulating layer.Moreover, the method may include forming an organic photoelectric layeron the electrode layer. In some embodiments, the method may includeetching the insulating layer to form an opening that exposes a portionof a metal structure. The metal structure may be adjacent a sidewall ofthe color filter layer.

In some embodiments, forming the electrode layer may include forming theelectrode layer in the opening of the insulating layer. Additionally oralternatively, the method may include forming a photoresist material ona portion of the insulating layer. Moreover, the method may includeperforming an etch of the insulating layer while the photoresistmaterial is on the portion of the insulating layer, to form a protrudingportion of the insulating layer. Forming the electrode layer may includeforming the electrode layer on the protruding portion of the insulatinglayer.

According to some embodiments, forming the transparent layer on thecolor filter layer may include forming the transparent layer on a redfirst color filter layer and a blue second color filter layer. Formingthe insulating layer may include forming an oxide layer on thetransparent layer. Moreover, forming the electrode layer may includeforming an indium tin oxide (ITO) layer on the oxide layer.

A method of forming an image sensor, according to some embodiments, mayinclude forming an insulating layer on a color filter layer. The methodmay include forming a photoresist material on a portion of theinsulating layer. The method may include etching the insulating layerwhile the photoresist material is on the portion of the insulatinglayer. Moreover, the method may include removing the photoresistmaterial to expose a protruding portion of the insulating layer.

In some embodiments, etching the insulating layer may include performinga first etch of the insulating layer. The method may include performinga second etch of the insulating layer to form an opening that at leastpartially exposes a metal structure that is adjacent a sidewall of thecolor filter layer. Moreover, the method may include forming anelectrode layer in the opening of the insulating layer.

According to some embodiments, the method may include performing a thirdetch of the insulating layer to form a recess that overlaps the metalstructure, without exposing the metal structure, before performing thesecond etch of the insulating layer. Additionally or alternatively,forming the electrode layer may include forming the electrode layer onthe protruding portion of the insulating layer.

In some embodiments, the protruding portion of the insulating layer mayoverlap the color filter layer. Forming the electrode layer may includedepositing an electrode material on the insulating layer, and performinga chemical mechanical polishing (CMP) process on the electrode materialuntil a surface of the protruding portion of the insulating layer isexposed. Moreover, the method may include forming an organicphotoelectric layer on the electrode layer and on the surface of theprotruding portion of the insulating layer that is exposed by the CMPprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingbrief description taken in conjunction with the accompanying drawings.The accompanying drawings represent non-limiting, example embodiments asdescribed herein.

FIG. 1 is a cross-sectional view illustrating a main portion of an imagesensor according to some embodiments of present inventive concepts.

FIG. 2 is a cross-sectional view illustrating a main portion of an imagesensor according to some embodiments of present inventive concepts.

FIGS. 3A to 3R are cross-sectional views illustrating a process ofmanufacturing an image sensor according to some embodiments of presentinventive concepts.

FIGS. 4A to 4E are cross-sectional views illustrating a process ofmanufacturing the image sensor according to some embodiments of presentinventive concepts.

FIGS. 5A to 5O are cross-sectional views illustrating a process ofmanufacturing the image sensor according to some embodiments of presentinventive concepts.

FIGS. 6A to 6E are cross-sectional views illustrating a process ofmanufacturing the image sensor according to some embodiments of presentinventive concepts.

FIG. 7 is a cross-sectional view illustrating a main portion of an imagesensor according to some embodiments of present inventive concepts.

FIG. 8 is a cross-sectional view illustrating a main portion of an imagesensor according to some embodiments of present inventive concepts.

FIG. 9 illustrates a readout circuit of an image sensor according tosome embodiments of present inventive concepts.

FIG. 10 illustrates a readout circuit of an image sensor according tosome embodiments of present inventive concepts.

FIG. 11 is a block diagram illustrating a configuration of an imagesensor according to some embodiments of present inventive concepts.

FIG. 12 is a block diagram of a system including an image sensoraccording to some embodiments of present inventive concepts.

FIG. 13 illustrates an electronic system including an image sensor andan interface according to some embodiments of present inventiveconcepts.

FIG. 14 is a perspective view schematically illustrating an electronicsystem to which an image sensor is applied according to some embodimentsof present inventive concepts.

DETAILED DESCRIPTION

Example embodiments are described below with reference to theaccompanying drawings. Many different forms and embodiments are possiblewithout deviating from the spirit and teachings of this disclosure andso the disclosure should not be construed as limited to the exampleembodiments set forth herein. Rather, these example embodiments areprovided so that this disclosure will be thorough and complete, and willconvey the scope of the disclosure to those skilled in the art. In thedrawings, the sizes and relative sizes of layers and regions may beexaggerated for clarity. Like reference numbers refer to like elementsthroughout the description.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the embodiments.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including,” when used in thisspecification, specify the presence of the stated features, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, steps, operations,elements, components, and/or groups thereof.

It will be understood that when an element is referred to as being“coupled,” “connected,” or “responsive” to, or “on,” another element, itcan be directly coupled, connected, or responsive to, or on, the otherelement, or intervening elements may also be present. In contrast, whenan element is referred to as being “directly coupled,” “directlyconnected,” or “directly responsive” to, or “directly on,” anotherelement, there are no intervening elements present. As used herein theterm “and/or” includes any and all combinations of one or more of theassociated listed items.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein may be interpreted accordingly.

Example embodiments of present inventive concepts are described hereinwith reference to cross-sectional illustrations that are schematicillustrations of idealized embodiments (and intermediate structures) ofexample embodiments. As such, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, example embodiments ofpresent inventive concepts should not be construed as limited to theparticular shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing.Accordingly, the regions illustrated in the figures are schematic innature and their shapes are not intended to illustrate the actual shapeof a region of a device and are not intended to limit the scope ofexample embodiments.

It will be understood that although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. Thus, a “first” element could be termed a“second” element without departing from the teachings of the presentembodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and/orthe present specification and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

As appreciated by the present inventive entity, devices and methods offorming devices according to various embodiments described herein may beembodied in microelectronic devices such as integrated circuits, whereina plurality of devices according to various embodiments described hereinare integrated in the same microelectronic device. Accordingly, thecross-sectional view(s) illustrated herein may be replicated in twodifferent directions, which need not be orthogonal, in themicroelectronic device. Thus, a plan view of the microelectronic devicethat embodies devices according to various embodiments described hereinmay include a plurality of the devices in an array and/or in atwo-dimensional pattern that is based on the functionality of themicroelectronic device.

The devices according to various embodiments described herein may beinterspersed among other devices depending on the functionality of themicroelectronic device. Moreover, microelectronic devices according tovarious embodiments described herein may be replicated in a thirddirection that may be orthogonal to the two different directions, toprovide three-dimensional integrated circuits.

Accordingly, the cross-sectional view(s) illustrated herein providesupport for a plurality of devices according to various embodimentsdescribed herein that extend along two different directions in a planview and/or in three different directions in a perspective view. Forexample, when a single active region is illustrated in a cross-sectionalview of a device/structure, the device/structure may include a pluralityof active regions and transistor structures (or image sensor structures,memory cell structures, gate structures, etc., as appropriate to thecase) thereon, as would be illustrated by a plan view of thedevice/structure.

FIG. 1 is a cross-sectional view illustrating a main portion of an imagesensor 1 according to some embodiments of present inventive concepts.

Referring to FIG. 1, the image sensor 1 includes a semiconductorsubstrate 200 including a first pixel area P1 and a second pixel areaP2. A device isolation layer 202 may be disposed on the semiconductorsubstrate 200. The device isolation layer 202 may define the first pixelarea P1 and the second pixel area P2.

The semiconductor substrate 200 may be, for example, one of a bulksubstrate, an epitaxial substrate, and a silicon on insulator (SOI)substrate. The semiconductor substrate 200 may include, for example,silicon. Also, the semiconductor substrate 200 may include asemiconductor element such as germanium (Ge) or a compound semiconductorsuch as silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide(InAs), and indium phosphide (InP). The semiconductor substrate 200 maybe formed based on a first conductivity-type semiconductor substrate.The semiconductor substrate 200 may be, for example, a P-typesemiconductor substrate.

A photoelectric transducer 204 may be disposed in the semiconductorsubstrate 200 to correspond to each of the first and second pixel areasP1 and P2. The photoelectric transducer 204 may be a photodiode. Thephotoelectric transducer 204 may include a first impurity area 204 a anda second impurity area 204 b. The first impurity area 204 a may beformed deeply from a surface of the semiconductor substrate 200. Thesecond impurity area 204 b may be formed shallowly in the surface of thesemiconductor substrate 200. The first impurity area 204 a and thesecond impurity area 204 b may include different conductivity types. Forexample, the first impurity area 204 a may be doped with N-typeimpurities, and the second impurity area 204 b may be doped with P-typeimpurities.

The photoelectric transducer 204 may include pixels which sense redlight and blue light. For example, a pixel which senses red light may bein the first pixel area P1 and a pixel which senses blue light may be inthe second pixel area P2. A storage node area 206 may be disposed in thesemiconductor substrate 200 to correspond to each of the first andsecond pixel areas P1 and P2 while being spaced apart from thephotoelectric transducer 204. The storage node area 206 may be, forexample, doped with N-type impurities. The storage node area 206 may beformed as a single doped area and may have a smaller area than that ofthe photoelectric transducer 204.

A wiring structure 220 is disposed on a first side 201 a of thesemiconductor substrate 200. A first contact hole 215 may be formed inthe wiring structure 220. A first side insulating layer 211 may beformed on a side of the first contact hole 215. A first contact via 213may completely fill the first contact hole 215 and may be in contactwith the first side insulating layer 211. A width of the first contacthole 215 may gradually increase as it gets farther from the surface ofthe semiconductor substrate 200. The first side insulating layer 211 maybe formed of an oxide or a nitride. The first contact via 213 may beformed of, for example, a metallic material such as copper, aluminum,and tungsten.

The wiring structure 220 may include a buffer area 217 which is incontact with the first contact via 213. The buffer area 217 may beelectrically connected to the storage node area 206 formed on thesemiconductor substrate 200 through the first contact via 213. Thebuffer area 217 may be formed of, for example, a metallic material suchas copper, aluminum, and tungsten or carbon nanotubes.

The wiring structure 220 may include a front interlayer dielectric 221and a plurality of front wires 223. The front interlayer dielectric 221may use a high density plasma (HDP) oxide film, a tetraethylorthosilicate (TEOS) oxide film, tonen silazene (TOSZ), spin on glass(SOG), undoped silica glass (USG), a low-k dielectric layer, etc. Theplurality of front wires 223 may be formed of, for example, a metallicmaterial such as copper, aluminum, and tungsten.

A supporting layer 290 may be adhered to the wiring structure 220. Thesupporting layer 290 may be used to provide strength to thesemiconductor substrate 200 which is thinned through a polishingprocess. In some embodiments, the supporting layer 290 may be formed ofa silicon oxide, a silicon nitride, and/or a semiconductor material.

The image sensor 1 may include a second contact hole 225 whichpenetrates and extends through the semiconductor substrate 200 from asecond side 201 b of the semiconductor substrate 200 to the buffer area217. A width of the second contact hole 225 may gradually increase as itapproaches the second side 201 b of the semiconductor substrate 200 fromthe buffer area 217. In some embodiments, the second contact hole 225may be formed to penetrate the device isolation layer 202.

A second side insulating layer 227 may be formed on a side of the secondcontact hole 225. The second side insulating layer 227 may be formed ofan oxide or a nitride. The second contact hole 225 may be filled with asecond contact via 229. The second contact via 229 may completely fillthe second contact hole 225 to be in contact with the second sideinsulating layer 227. Accordingly, the second contact via 229 maypenetrate the semiconductor substrate 200. The second contact via 229may be, for example, formed of a metallic material such as copper,aluminum, and tungsten.

A stud layer 230 electrically connected to the second contact via 229may be formed on the second side 201 b of the semiconductor substrate200. The stud layer 230 may include a first stud layer 231 formed on thesecond side 201 b of the semiconductor substrate 200 and a second studlayer 233 formed on the first stud layer 231. The second stud layer 233may be formed to surround side and top surfaces of the first stud layer231, thereby having a larger width than that of the first stud layer231. The first stud layer 231 and the second stud layer 233 may beformed of different metallic materials. In some embodiments, the firststud layer 231 may be formed of tungsten and the second stud layer 233may be formed of aluminum. The stud layer 230 may have a first width W1.When the second stud layer 233 has a larger width than that of the firststud layer 231, the second stud layer 233 may have the first width W1.

Although the first width W1 of the second stud layer 233 is illustratedin FIG. 1 as being substantially constant throughout the height of thesecond stud layer 233, the second stud layer 233 may alternatively besloped/tapered toward an overlying lower transparent electrode layer266. For example, sidewalls of the second stud layer 233 may be taperedtoward (i.e., a distance between the sidewalls may narrow as thesidewalls are closer to) the lower transparent electrode layer 266.Additionally or alternatively, the stud layer 230 may be referred toherein as a “metal structure” or a “metal region” and is not limited tothe term “stud.”

A color filter layer 240 may be formed on the second side 201 b of thesemiconductor substrate 200. The color filter layer 240 may allow lightincident through a micro lens 280 to pass, thereby allowing only lightwith a necessary wavelength to be incident on the photoelectrictransducer 204 through the second side 201 b. In some embodiments, ananti-reflection layer may be formed between the second side 201 b andthe color filter layer 240 of the semiconductor substrate 200 to allowlight to be incident on the photoelectric transducer 204 byreducing/preventing the reflection of light. The anti-reflection layermay be formed of, for example, silicon oxynitride (SiON), siliconcarbide (SiC), silicon carbon nitride (SiCN), silicon oxycarbide (SiCO),etc.

The color filter layer 240 may include a first color filter layer 241and a second color filter layer 243. The first color filter layer 241and the second color filter layer 243 may be disposed in the first pixelarea P1 and the second pixel area P2 to correspond to the photoelectrictransducers 204 formed therein, respectively. In some embodiments, thefirst color filter layer 241 disposed in the first pixel area P1 may bea red (R) color filter and the second color filter layer 243 disposed inthe second pixel area P2 may be a blue (B) color filter. Accordingly,the first pixel area P1 transmits light with a red wavelength to allowthe red wavelength to arrive at the photoelectric transducer 204. Also,the second pixel area P2 transmits light with a blue wavelength to allowthe blue wavelength to arrive at the photoelectric transducer 204.

The color filter layer 240 may be formed to have a top surface with alower level than that of the stud layer 230. That is, a height of thecolor filter layer 240 may be formed to have a smaller value than thatof the stud layer 230.

A coating layer 245, which covers the color filter layer 240, may beformed on the second side 201 b of the semiconductor substrate 200. Thecoating layer 245 may be formed by forming a coating material layerwhich covers a top of the semiconductor substrate 200 on which the studlayer 230 and the color filter layer 240 are formed and performing aplanarization process. The coating layer 245 may expose a top surface ofthe stud layer 230. The coating layer 245 and the stud layer 230 mayhave top surfaces with the same level. That is, the top surfaces of thecoating layer 245 and the stud layer 230 may form planes with the samelevel (i.e., the top surfaces may be coplanar). The coating layer 245may be formed by forming the coating material layer and then removing apart of the coating material layer until the top surface of the studlayer 230 is exposed. The coating layer 245 may be formed of atransparent organic material. In some embodiments, the coating layer 245may be formed of resin. The coating layer 245 may be on top of (e.g.,may directly contact top surfaces of) a plurality of color filter layers240.

The coating layer 245 may be referred to herein as a “transparent layer”and is not limited to the term “coating.” Additionally or alternatively,the coating layer 245 may be a silicon oxide layer.

An isolation-insulating layer 260 c having a plurality of openings 262His formed on the coating layer 245. The plurality of openings 262H maypass through the isolation-insulating layer 260 c.

The isolation-insulating layer 260 c may be formed of, for example, anoxide. The isolation-insulating layer 260 c may include a base layer 262and an isolation layer 264 formed on the base layer 262. The base layer262 may have the opening 262H which exposes at least a part of the studlayer 230. An isolation space 260D defined by the isolation-insulatinglayer 260 c, that is, the base layer 262 and the isolation layer 264,may be formed. A plurality of such isolation spaces 260D may be formedto correspond to a plurality of pixel areas P1 and P2.

The isolation space 260D refers to a portion/region/area between abottom surface level and a top surface level of the isolation-insulatinglayer 260 c where the isolation-insulating layer 260 c is not formed.That is, the isolation space 260D may include a space surrounded by theisolation layer 264 between levels of a top surface of the base layer262 and a top surface of the isolation layer 264 and a space in theopening 262H. The plurality of isolation spaces 260D which are isolatedfrom each other may be formed to correspond to the plurality of pixelareas P1 and P2. That is, each of the plurality of isolation spaces 260Dmay be formed to correspond to a respective one of the plurality ofphotoelectric transducers 204.

A second width W2, which is a width of the opening 262H, may have asmaller value than that of the first width W1 of the stud layer 230. Thecoating layer 245 may not be exposed and a top surface thereof may becompletely covered due to the isolation-insulating layer 260 c havingthe openings 262H. That is, the top surface of the coating layer 245 maybe totally covered by the isolation-insulating layer 260 c so as not tobe exposed at a bottom of the opening 262H. However, in someembodiments, a part of the coating layer 245 may be exposed at/via thebottom of the opening 262H.

A lower transparent electrode layer 266 which fills the isolation space260D is formed on the isolation-insulating layer 260 c. The lowertransparent electrode layer 266 may include a lower contact 266C, whichfills an inside of the opening 262H, and a lower electrode 266E, whichis connected to the lower contact 266C and disposed on the top surfaceof the base layer 262.

That is, the lower transparent electrode layer 266 may be formed to fillthe isolation space 260D using a dual damascene method. Accordingly, thelower contact 266C and the lower electrode 266E may besimultaneously/integrally formed. A top surface of the lower transparentelectrode layer 266 and a topmost end of the isolation-insulating layer260 c may have the same level. The top surface of the lower transparentelectrode layer 266 and the top surface of the isolation layer 264 mayhave the same level. That is, the top surface of the lower transparentelectrode layer 266 and the top surface of the isolation layer 264 mayform planes with the same level (i.e., the top surfaces may becoplanar).

Due to the isolation layer 264, the lower transparent electrode layer266 may be separated so as to correspond to each of the first pixel areaP1 and the second pixel area P2. That is, a plurality of such lowertransparent electrode layers 266 may be formed to correspond to theplurality of pixel areas P1 and P2. In detail, the lower contact 266Cand the lower electrode 266E, which form the lower transparent electrodelayer 266 filling a single isolation space 260D, may be integrallyformed.

The coating layer 245 may not be exposed at the bottom of the opening262H. In this case, the coating layer 245 may be spaced apart to not bein contact with the lower transparent electrode layer 266. However, insome embodiments, a part of the coating layer 245 may be in contact withthe lower transparent electrode layer 266.

An organic photoelectric layer 272 is formed on the lower transparentelectrode layer 266. The organic photoelectric layer 272 may beintegrally formed on a plurality of lower transparent electrode layers266. The organic photoelectric layer 272 may be formed of an organicmaterial which causes a photoelectric change only in light with aparticular wavelength. For example, the organic photoelectric layer 272may cause the photoelectric change only at a wavelength of green light.For example, the organic photoelectric layer 272 may show a maximumabsorption wavelength λmax from about 500 nanometers (nm) to about 600nm in both of the first and second pixel areas P1 and P2.

The organic photoelectric layer 272, in which a P-type semiconductormaterial and an N-type semiconductor material form a PN flat junction ora bulk heterojuction, may be formed of a single layer or multiplelayers, and is a layer which receives incident light, generates anexciton, and then separates the generated exciton into a positive holeand an electron.

The P-type semiconductor material and the N-type semiconductor materialmay each absorb light of a green wavelength area and may each show amaximum absorption peak in a wavelength area of from about 500 nm toabout 600 nm.

The P-type semiconductor material and the N-type semiconductor materialmay each have, for example, a bandgap within the range of about 1.5 eVto about 3.5 eV and, within this range, may each have a bandgap withinthe range of about 2.0 eV to about 2.5 eV. The P-type semiconductormaterial and the N-type semiconductor material may absorb the light ofthe green wavelength area by having the bandgap within that range andparticularly may each show the maximum absorption peak in a wavelengtharea of from about 500 nm to about 600 nm.

The P-type semiconductor material and the N-type semiconductor materialmay each have a full width at half maximum (FWHM) of from about 50 nm toabout 150 nm in a light absorption curve. Here, the FWHM is a width of awavelength corresponding to half of a maximum light absorption point. Asmall FWHM indicates that light in a narrow wavelength area isselectively absorbed in such a way that wavelength selectivity is high.With an FWHM within the range, selectivity for the green wavelength areamay be high.

A difference between a lowest unoccupied molecular orbital (LUMO) energylevel of the P-type semiconductor material and an LUMO energy level ofthe N-type semiconductor material may be from about 0.2 to about 0.7 eV.For example, within this range, the difference may be from about 0.3 toabout 0.5 eV. As the P-type semiconductor material and the N-typesemiconductor material of the organic photoelectric layer 272 have thedifference within that range in the LUMO energy level, external quantumefficiency (EQE) may be improved and EQE may be effectively controlledaccording to applied bias.

The P-type semiconductor material may include, for example, a compoundsuch as N,N′-dimethyl-quinacridone (DMQA) and derivatives thereof,diindenoperylene, anddibenzo{[f,f′]-4,4′,7,7′-tetraphenyl}diindeno[1,2,3-cd:1′,2′,3′-1m]perylenebut is not limited thereto. The N-type semiconductor material mayinclude, for example, a compound such as dicyanovinyl-terthiophene(DCV3T) and derivatives thereof, perylene diimide, phtalocyanine andderivatives thereof, subphtalocyanine and derivatives thereof, borondipyrromethene (BODIPY) and derivatives thereof but is not limitedthereto.

The organic photoelectric layer 272 may be a single layer and may bemultiple layers. The organic photoelectric layer 272 may have, forexample, various combinations such as an intrinsic layer (I-layer), aP-type layer/I-layer, an I-layer/N-type layer, a P-typelayer/I-layer/N-type layer, a P-type layer/N-type layer, etc.

The I-layer may include the P-type semiconductor compound and the N-typesemiconductor compound mixed at a ratio of from about 1:100 to about100:1. Within this range, the ratio may be from about 1:50 to about50:1. Within this range, the ratio may be from about 1:10 to about 10:1.For example, within this range, the ratio may be about 1:1. As a P-typesemiconductor and an N-type semiconductor have a composition ratiowithin that ratio, an exciton may be effectively generated and aPN-junction may be formed according to desired specifications.

A P-type layer may include the P-type semiconductor compound, and anN-type layer may include the N-type semiconductor compound.

The organic photoelectric layer 272 may have, for example, a thicknessfrom about 1 nm to about 500 nm. In some embodiments, the organicphotoelectric layer 272 may have a thickness from about 5 nm to about300 nm. The organic photoelectric layer 272 may have a thickness capableof effectively improving photoelectric conversion efficiency byeffectively absorbing light and effectively separating and transferringpositive holes and electrons.

An upper transparent electrode layer 274 is formed on the organicphotoelectric layer 272. The upper transparent electrode layer 274 maybe formed of, for example, indium tin oxide (ITO), indium zinc oxide(IZO), zinc oxide (ZnO), stannic oxide (SnO₂), antimony-doped tin oxide(ATO), Aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO),titanium dioxide (TiO₂), or fluorine-doped tin oxide (FTO). The uppertransparent electrode layer 274 may be integrally formed across thefirst pixel area P1 and the second pixel area P2.

The micro lens 280 corresponding to the color filter layer 240 is formedon the upper transparent electrode layer 274. The micro lens 280 may beformed to overlap the corresponding color filter layer 240. A pluralityof such micro lenses 280 may be formed to correspond to a plurality ofrespective color filter layers 240. The micro lens 280 may change a pathof light incident on areas except (e.g., other than) the photoelectrictransducer 204, and may concentrate the light on the photoelectrictransducer 204.

In some embodiments, a protective layer 278 may be further formedbetween the micro lens 280 and the upper transparent electrode layer274. The protective layer 278 may be formed of a transparent insulatingmaterial.

FIG. 2 is a cross-sectional view illustrating a main portion of an imagesensor 2 according to some embodiments of present inventive concepts. Inthe description of FIG. 2, content/descriptions duplicated withreference to FIG. 1 may be omitted.

Referring to FIG. 2, the image sensor 2 includes a semiconductorsubstrate 300 including a first pixel area P1 and a second pixel areaP2. A device isolation layer 302 may be disposed on the semiconductorsubstrate 300. The device isolation layer 302 may define the first pixelarea P1 and the second pixel area P2.

A photoelectric transducer 304 may be disposed in the semiconductorsubstrate 300 to correspond to each of the first and second pixel areasP1 and P2. The photoelectric transducer 304 may be a photodiode. Thephotoelectric transducer 304 may include a first impurity area 304 a anda second impurity area 304 b. The first impurity area 304 a may beformed deeply from a top surface of the semiconductor substrate 300. Thesecond impurity area 304 b may be formed shallowly at the top surface ofthe semiconductor substrate 300. The first impurity area 304 a and thesecond impurity area 304 b may include different conductivity types. Forexample, the first impurity area 304 a may be doped with N-typeimpurities, and the second impurity area 304 b may be doped with P-typeimpurities.

The photoelectric transducer 304 may be disposed in pixels which sensered light and blue light. For example, a pixel which senses red lightmay be the first pixel area P1 and a pixel which senses blue light maybethe second pixel area P2. A storage node area 306 may be disposed in thesemiconductor substrate 300 to correspond to each of the first andsecond pixel areas P1 and P2 while being spaced apart from thephotoelectric transducer 304. The storage node area 306 may be, forexample, doped with N-type impurities. The storage node area 306 may beformed as a single doped area and may have a smaller area than that ofthe photoelectric transducer 304.

An interlayer dielectric structure 310 may be disposed on thesemiconductor substrate 300. The interlayer dielectric structure 310 mayinclude a plurality of interlayer dielectrics 311, 312, 313, and 314sequentially deposited on the semiconductor substrate 300 and an etchingstopper 316 disposed on a top surface of the plurality of interlayerdielectrics (e.g., dielectric layers) 311, 312, 313, and 314. In someembodiments, the interlayer dielectric 314 at a topmost end of theplurality of interlayer dielectrics 311, 312, 313, and 314 may be formedthicker than the other interlayer dielectrics 311, 312, and 313. Theplurality of interlayer dielectrics 311, 312, 313, and 314 may be formedof oxides. For example, the plurality of interlayer dielectrics 311,312, 313, and 314 may be formed of an HDP oxide film, a TEOS oxide film,TOSZ, SOG, USG, a low-k dielectric layer, etc. The etching stopper 316may be formed of a silicon nitride film or a silicon oxynitride film.

A wiring structure 320 is disposed in each of the first pixel area P1and the second pixel area P2 on the semiconductor substrate 300. Thewiring structure 320 may be formed of, for example, a metallic materialsuch as copper, aluminum, and tungsten. For example, the wiringstructure 320 may include interlayer wires 321 disposed in at least apart of the plurality of interlayer dielectrics 311, 312, 313, and 314and contact vias 323 which pass through the plurality of interlayerdielectrics 311, 312, 313, and 314 and connect the interlayer wires 321.The contact vias 323 may include a bottommost contact via 323 a, anintermediate contact via 323 b, and a topmost contact via 323 c. Thebottommost contact via 323 a may be in contact with the storage nodearea 306.

In some embodiments, a buffer via 325 may be provided between thebottommost contact via 323 a and the storage node area 306. The buffervia 325 may include, for example, carbon nanotubes. The buffer via 325may provide, for example, a material with a work function between ametal and silicon to reduce an energy barrier between the semiconductorsubstrate 300 and the wiring structure 320, thereby providing adequateohmic contact. For example, a work function of silicon may be 4.05 eV inthe semiconductor substrate 300, a work function of a metal (forexample, copper) may be 4.70 eV in the wiring structure 320, and a workfunction of the buffer via 325 (for example, carbon nanotubes) may befrom about 4.3 eV to about 4.8 eV. The buffer via 325 may reduce anenergy barrier between the silicon and the metal to allow electronsand/or positive holes to be better transferred to the storage node area306 through the wiring structure 320.

A stud layer 330 electrically connected with the topmost contact via 323c may be formed on the interlayer dielectric structure 310. The studlayer 330 may include a first stud layer 331 formed on the interlayerdielectric structure 310 and a second stud layer 333 formed on the firststud layer 331. The second stud layer 333 may have a larger width thanthat of the first stud layer 331 to surround side and top surfaces ofthe first stud layer 331. The first stud layer 331 and the second studlayer 333 may be formed of different metallic materials. In someembodiments, the first stud layer 331 may be formed of tungsten and thesecond stud layer 333 may be formed of aluminum. The stud layer 330 mayhave a first width W1. When the second stud layer 333 has a larger widththan that of the first stud layer 331, the second stud layer 333 mayhave the first width W1.

A color filter layer 340 may be formed on the interlayer dielectricstructure 310. The color filter layer 340 may transmit light incidentthrough a micro lens 380 to allow only light with a necessary wavelengthto be incident on the photoelectric transducer 304. In some embodiments,an anti-reflection layer may be formed between the interlayer dielectricstructure 310 and the color filter layer 340 to allow light to beincident on the photoelectric transducer 304 by reducing/preventing thereflection of light. The anti-reflection layer may be formed of, forexample, SiON, SiC, SiCN, SiCO, etc.

The color filter layer 340 may include a first color filter layer 341and a second color filter layer 343. The first color filter layer 341and the second color filter layer 343 may be disposed in the pixel areaP1 and the second pixel area P2, respectively. In some embodiments, thefirst color filter layer 341 disposed in the first pixel area P1 may bea red (R) color filter and the second color filter layer 343 disposed inthe second pixel area P2 may be a blue (B) color filter. Accordingly,the first pixel area P1 transmits light with a red wavelength to allowthe red wavelength to arrive at the photoelectric transducer 304. Also,the second pixel area P2 transmits light with a blue wavelength to allowthe blue wavelength to arrive at the photoelectric transducer 304.

The color filter layer 340 may have a top surface with a lower levelthan that of the stud layer 330. That is, a height of the color filterlayer 340 may be a smaller value than that of the stud layer 330.

A coating layer 345 may be formed on the interlayer dielectric structure310. The coating layer 345 may cover the color filter layer 340. Thecoating layer 345 may be formed by forming a coating material layerwhich covers a top of the interlayer dielectric structure 310 on whichthe stud layer 330 and the color filter layer 340 are formed andperforming a planarization process. The coating layer 345 may expose atop surface of the stud layer 330. The coating layer 345 and the studlayer 330 may have top surfaces with the same level. That is, the topsurfaces of the coating layer 345 and the stud layer 330 may form planeswith the same level (i.e., the top surfaces may be coplanar). Thecoating layer 345 may be formed by forming the coating material layerand then removing a part of the coating material layer until the topsurface of the stud layer 330 is exposed. The coating layer 345 may beon top of (e.g., may directly contact top surfaces of) a plurality ofcolor filter layers 340.

An isolation-insulating layer 360 c may be formed on the interlayerdielectric structure 310 on which the coating layer 345 is formed. Theisolation-insulating layer 360 c may be formed of, for example, anoxide. The isolation-insulating layer 360 c may include a base layer 362and an isolation layer 364 formed on the base layer 362. The base layer362 may have an opening 362H which exposes at least a part of the studlayer 330. An isolation space 360D defined by the isolation-insulatinglayer 360 c, that is, the base layer 362 and the isolation layer 364,may be formed. A plurality of such isolation spaces 360D may be formedto correspond to the plurality of pixel areas P1 and P2.

The isolation space 360D refers to a portion/region/area between abottom surface level and a top surface level of the isolation-insulatinglayer 360 c where the isolation-insulating layer 360 c is not formed.That is, the isolation space 360D may include a space surrounded by theisolation layer 364 between levels of a top surface of the base layer362 and a top surface of the isolation layer 364 and a space in theopening 362H. The plurality of isolation spaces 360D which are isolatedfrom each other may be formed to correspond to the plurality of pixelareas P1 and P2. That is, each of the plurality of isolation spaces 360Dmay be formed to correspond to a respective one of the plurality ofphotoelectric transducers 304.

A second width W2, which is the width of the opening 362H, may have asmaller value than that of the first width W1 of the stud layer 330. Thecoating layer 345 may not be exposed and a top surface thereof may becompletely covered due to the isolation-insulating layer 360 c havingthe opening 362H. That is, the top surface of the coating layer 345 maybe totally covered by the isolation-insulating layer 360 c so as not tobe exposed at a bottom of the opening 362H. However, in someembodiments, a part of the coating layer 345 may be exposed at thebottom of the opening 362H, which will be described below in detail withreference to FIG. 8.

A lower transparent electrode layer 366, which fills the isolation space360D, may be formed on the isolation-insulating layer 360 c. The lowertransparent electrode layer 366 may be formed of, for example, ITO, IZO,ZnO, SnO₂, ATO, AZO, GZO, TiO₂, or FTO. That is, the lower transparentelectrode layer 366 may be formed to fill the isolation space 360D usinga dual damascene method. The lower transparent electrode layer 366 maybe formed by forming a lower transparent material layer which covers atop of the isolation-insulating layer 360 c to fill the isolation space360D and then performing a planarization process until theisolation-insulating layer 360 c, that is, the isolation layer 364, isexposed. The planarization process for forming the lower transparentelectrode layer 366 may be performed by a chemical-mechanicalplanarization (CMP) process.

Accordingly, the lower transparent electrode layer 366 may include alower contact 366C, which fills an inside of the opening 362H, and alower electrode 366E, which is connected to the lower contact 366C anddisposed on the top surface of the base layer 362. The lower contact366C and the lower electrode 366E may be integrally formed. A topsurface of the lower transparent electrode layer 366 and a topmost endof the isolation-insulating layer 360 c may have the same level. Inparticular, the top surface of the lower transparent electrode layer 366and the top surface of the isolation layer 364 may have the same level.That is, the top surface of the lower transparent electrode layer 366and the top surface of the isolation layer 364 may form planes with thesame level (i.e., the top surfaces may be coplanar).

Due to the isolation layer 364, the lower transparent electrode layer366 may be separated to correspond to each of the first pixel area P1and the second pixel area P2. That is, a plurality of such separatedlower transparent electrode layers 366 may be formed to correspond tothe plurality of pixel areas P1 and P2. In detail, the lower contact366C and the lower electrode 366E, which form the lower transparentelectrode layer 366 filling a single isolation space 360D, may beintegrally formed.

When the coating layer 345 is not exposed at the bottom of the opening362H, the coating layer 345 may be spaced apart to not be in contactwith the lower transparent electrode layer 366. However, in someembodiments, a part of the coating layer 345 may be in contact with thelower transparent electrode layer 366, which will be described below indetail with reference to FIG. 8.

An organic photoelectric layer 372 and an upper transparent electrodelayer 374 are sequentially disposed on the lower transparent electrodelayer 366. The organic photoelectric layer 372 may be integrally formedon the plurality of lower transparent electrode layers 366. The organicphotoelectric layer 372 may be an organic material which causes aphotoelectric change only in light with a particular wavelength. Forexample, the organic photoelectric layer 372 may cause the photoelectricchange only at a wavelength of green light. For example, the organicphotoelectric layer 372 may show a maximum absorption wavelength λmaxfrom about 500 nm to about 600 nm in both of the first and second pixelareas P1 and P2.

The upper transparent electrode layer 374 may be integrally (e.g.,continuously) formed across the first pixel area P1 and the second pixelarea P2. The micro lens 380 corresponding to the color filter layer 340is disposed on the upper transparent electrode layer 374. In someembodiments, a protective layer 378 may be further formed between themicro lens 380 and the upper transparent electrode layer 374. Theprotective layer 378 may be formed of a transparent insulating material.The micro lens 380 may be formed to overlap with the corresponding colorfilter layer 340. A plurality of such micro lenses 380 may be formedcorresponding to respective ones of the plurality of color filter layers340.

The micro lens 380 may change a path of light incident on areas except(e.g., other than) the photoelectric transducer 304, and may concentratethe light on the photoelectric transducer 304.

FIGS. 3A to 3R are cross-sectional views illustrating a process ofmanufacturing an image sensor according to some embodiments of presentinventive concepts. In detail, FIGS. 3A to 3R are cross-sectional viewsillustrating a process of manufacturing the image sensor 1 shown inFIG. 1. In the description of FIGS. 3A to 3R, content/descriptionsduplicated with reference to FIG. 1 may be omitted.

Referring to FIG. 3A, the semiconductor substrate 200 having a pluralityof pixel areas defined by the device isolation layer 202 is prepared.The plurality of photoelectric transducers 204 and the plurality ofstorage node areas 206 spaced apart from the plurality of photoelectrictransducers 204 are formed in the plurality of pixel areas of thesemiconductor substrate 200, respectively.

The semiconductor substrate 200 may be, for example, any one of a bulksubstrate, an epitaxial substrate, and an SOI substrate. Thesemiconductor substrate 200 may include, for example, silicon. Also, thesemiconductor substrate 200 may include a semiconductor element such asGe or a compound semiconductor such as SiC, GaAs, InAs, and InP. Thesemiconductor substrate 200 may be formed based on a firstconductivity-type semiconductor substrate. The semiconductor substrate200 may be, for example, a P-type semiconductor substrate.

The plurality of photoelectric transducers 204 may be formed to bearranged in the semiconductor substrate 200. Each of the plurality ofphotoelectric transducers 204 may be disposed in the semiconductorsubstrate 200 to correspond to each of the plurality of pixel areas. Thephotoelectric transducer 204 may be formed deeply from a surface of thesemiconductor substrate 200. The photoelectric transducer 204 mayinclude the first impurity area 204 a and the second impurity area 204b. The first impurity area 204 a may be formed deeply from a surface ofthe semiconductor substrate 200, and the second impurity area 204 b maybe formed shallowly from the surface. The first impurity area 204 a andthe second impurity area 204 b may have different conductivity types.For example, the first impurity area 204 a may be an area doped withN-type impurities, and the second impurity area 204 b may be an areadoped with P-type impurities.

The plurality of storage node areas 206 spaced apart from the pluralityof photoelectric transducers 204 and in contact with or adjacent to thesurface of the semiconductor substrate 200 are formed in the pluralityof pixel areas of the semiconductor substrate 200, respectively. Thestorage node area 206 may be an impurity area doped with N-typeimpurities. The storage node area 206 may be formed as a single dopedarea, and may have a smaller area than that of the photoelectrictransducer 204.

Referring to FIG. 3B, the wiring structure 220 is disposed on the firstside 201 a of the semiconductor substrate 200.

In the wiring structure 220, the first contact hole 215 is formed, thefirst side insulating layer 211 is formed on a side of the first contacthole 215, the first contact hole 215 is completely filled, and the firstcontact via 213 in contact with the first side insulating layer 211 isformed. A width of the first contact hole 215 may gradually increase asit moves upward from the surface of the semiconductor substrate 200. Thefirst side insulating layer 211 may be formed of an oxide or a nitride.The first contact via 213 may be formed of, for example, a metallicmaterial such as copper, aluminum, and tungsten.

After that, the buffer area 217 adjacent to the semiconductor substrate200 and in contact with the first contact via 213 is formed.

The buffer area 217 may be electrically connected to the storage nodearea 206 formed on the semiconductor substrate 200 through the firstcontact via 213. The buffer area 217 may include, for example, ametallic material such as copper, aluminum, and tungsten or carbonnanotubes.

The wiring structure 220 may include the front interlayer dielectric 221and the plurality of front wires 223. The front interlayer dielectric221 may include an HDP oxide film, a TEOS oxide film, TOSZ, SOG, USG, alow-k dielectric layer, etc. The plurality of front wires 223 mayinclude, for example, a metallic material such as copper, aluminum, andtungsten.

The supporting layer 290 may be adhered to the wiring structure 220. Thesupporting layer 290 may be used to provide strength to thesemiconductor substrate 200 which is thinned through a polishingprocess. In some embodiments, the supporting layer 290 may be formed ofa silicon oxide, a silicon nitride, and/or a semiconductor material.

Referring to FIG. 3C, the semiconductor substrate 200 is turned over(e.g., flipped/rotated) to allow the wiring structure 220 to be disposedbelow the semiconductor substrate 200. After that, a part of a top ofthe semiconductor substrate 200, that is, a bottom of the semiconductorsubstrate 200 shown in FIG. 3B distinguished by a dotted/broken line, isremoved

Referring to FIG. 3D, the second contact hole 225 which penetrates andextends through the semiconductor substrate 200 from the second side 201b of the semiconductor substrate 200 to the buffer area 217 is formed. Awidth of the second contact hole 225 may gradually increase as itapproaches the second side 201 b of the semiconductor substrate 200 fromthe buffer area 217. In some embodiments, the second contact hole 225may be formed to penetrate the device isolation layer 202.

The second side insulating layer 227 may be formed on a side of thesecond contact hole 225. The second side insulating layer 227 may beformed of an oxide or a nitride. The second contact hole 225 may befilled with the second contact via 229. The second contact via 229 maycompletely fill the second contact hole 225 to be in contact with thesecond side insulating layer 227. Accordingly, the second contact via229 may penetrate the semiconductor substrate 200. The second contactvia 229 may be formed of, for example, a metallic material such ascopper, aluminum, and tungsten.

Referring to FIG. 3E, the stud layer 230 electrically connected with thesecond contact via 229 may be formed on the second side 201 b of thesemiconductor substrate 200. The stud layer 230 may include the firststud layer 231 formed on the second side 201 b of the semiconductorsubstrate 200 and the second stud layer 233 formed on the first studlayer 231. The second stud layer 233 may be formed to surround side andtop surfaces of the first stud layer 231, thereby having a larger widththan that of the first stud layer 231. The first stud layer 231 and thesecond stud layer 233 may be formed of different metallic materials. Insome embodiments, the first stud layer 231 may be formed of tungsten andthe second stud layer 233 may be formed of aluminum. The stud layer 230may have the first width W1. When the second stud layer 233 has a largerwidth than that of the first stud layer 231, the second stud layer 233may have the first width W1.

Referring to FIG. 3F, the color filter layer 240 may be formed on thesecond side 201 b of the semiconductor substrate 200. The color filterlayer 240 may allow light incident through the micro lens 280 to pass,thereby allowing only light with a necessary wavelength to be incidenton the photoelectric transducer 204 through the second side 201 b. Insome embodiments, an anti-reflection layer may be formed between thesecond side 201 b and the color filter layer 240 of the semiconductorsubstrate 200 to allow light to be incident on the photoelectrictransducer 204 by reducing/preventing the reflection of light. Theanti-reflection layer may be formed of, for example, SiON, SiC, SiCN,SiCO, etc.

The color filter layer 240 may include the first color filter layer 241and the second color filter layer 243. The first color filter layer 241and the second color filter layer 243 may be disposed in the pixel areaP1 and the second pixel area P2 to correspond to the photoelectrictransducers 204 formed therein, respectively. In some embodiments, thefirst color filter layer 241 disposed in the first pixel area P1 may bea red (R) color filter and the second color filter layer 243 disposed inthe second pixel area P2 may be a blue (B) color filter. Accordingly,the first pixel area P1 transmits light with a red wavelength to allowthe red wavelength to arrive at the photoelectric transducer 204. Also,the second pixel area P2 transmits light with a blue wavelength to allowthe blue wavelength to arrive at the photoelectric transducer 204.

The color filter layer 240 may be formed to have a top surface with alower level than that of the stud layer 230. That is, a height of thecolor filter layer 240 may be formed to have a smaller value than thatof the stud layer 230.

Referring to FIG. 3G, the coating layer 245 may be formed on the secondside 201 b of the semiconductor substrate 200. The coating layer 245 maycover the color filter layer 240. The coating layer 245 may be formed byforming a coating material layer which covers a top of the semiconductorsubstrate 200 on which the stud layer 230 and the color filter layer 240are formed and performing a planarization process. The coating layer 245may expose a top surface of the stud layer 230. The coating layer 245and the stud layer 230 may have top surfaces with the same level. Thatis, the top surfaces of the coating layer 245 and the stud layer 230 mayform planes with the same level (i.e., the top surfaces may becoplanar). The coating layer 245 may be formed by forming the coatingmaterial layer and then removing a part of the coating material layeruntil the top surface of the stud layer 230 is exposed. The coatinglayer 245 may be formed of a transparent organic material. In someembodiments, the coating layer 245 may be formed of a resin. The coatinglayer 245 may be on top of (e.g., may directly contact top surfaces of)the plurality of color filter layers 240.

Referring to FIG. 3H, a preliminary insulating layer 260 which coversthe coating layer 245 and the stud layer 230 is formed. After that, afirst photoresist layer M1 is formed on the preliminary insulating layer260. The first photoresist layer M1 may be formed at a positioncorresponding to the isolation layer 264 shown in FIG. 1.

Referring to FIG. 3I, with the first photoresist layer M1 as an etchingmask, a preliminary insulating layer 260 a with a protruding portion 263formed on a top thereof is formed by removing a part from a top surfaceof the preliminary insulating layer 260 in FIG. 3H. The preliminaryinsulating layer 260 a may include a base portion 261, which covers thecoating layer 245 and the stud layer 230, and the protruding portion263, which protrudes from the base portion 261.

Referring to FIG. 3J, the first photoresist layer M1 in FIG. 3I isremoved. The first photoresist layer M1 may be removed by an ashingprocess.

Referring to FIG. 3K, a second photoresist layer M2 with a resist holeM2H which exposes a part of the preliminary insulating layer 260 ahaving the protruding portion 263 is formed. The resist hole M2H may bedisposed at a position corresponding to the opening 262H shown inFIG. 1. The second photoresist layer M2 may cover the entire protrudingportion 263.

Referring to FIG. 3L, with the second photoresist layer M2 as an etchingmask, a preliminary insulating layer 260 b with a plurality of recessedportions 261R is formed by removing a part of the preliminary insulatinglayer 260 a in FIG. 3K. The plurality of recessed portions 261R may bedisposed at positions corresponding to the openings 262H shown in FIG.1.

The plurality of recessed portions 261R may be formed to not completelypass through the preliminary insulating layer 260 b. Accordingly, evenwhen a misalignment occurs during a process of forming the secondphotoresist layer M2, the coating layer 245 may not be exposed atbottoms of the plurality of recessed portions 261R.

Referring to FIG. 3M, the second photoresist layer M2 in FIG. 3L isremoved. The second photoresist layer M2 may be removed by an ashingprocess.

The coating layer 245 may have properties similar to those of the secondphotoresist layer M2, for example, a property of being removed by theashing process. Accordingly, when the coating layer 245 is exposed atthe bottoms of the plurality of recessed portions 261R, at least a partof the coating layer 245 may be removed during a process of removing thesecond photoresist layer M2. However, since the plurality of recessedportions 261R may be formed to not completely pass through thepreliminary insulating layer 260 b in such a way that the coating layer245 is not exposed at the bottoms of the plurality of recessed portions261R, it is possible to protect/prevent at least a portion of thecoating layer 245 from being removed during the process of removing thesecond photoresist layer M2.

Referring to FIG. 3N, the isolation-insulating layer 260 c with theplurality of openings 262H is formed by removing a portion from a top ofthe preliminary insulating layer 260 b in FIG. 3M having the pluralityof recessed portions 261R in FIG. 3M and the protruding portion 263. Theplurality of openings 262H may be formed by removing a portion of thepreliminary insulating layer 260 b from the bottoms of the plurality ofrecessed portions 261R. The plurality of openings 262H may pass throughthe isolation-insulating layer 260 c.

The isolation-insulating layer 260 c may be formed of, for example, anoxide. The isolation-insulating layer 260 c may include the base layer262 and the isolation layer 264 formed on the base layer 262. The baselayer 262 may have the opening 262H which exposes at least a part of thestud layer 230. The isolation space 260D defined by theisolation-insulating layer 260 c, that is, the base layer 262 and theisolation layer 264, may be formed. A plurality of isolation spaces 260Dmay be formed to correspond to the plurality of pixel areas P1 and P2.

The isolation space 260D refers to a portion/region/area between abottom surface level and a top surface level of the isolation-insulatinglayer 260 c where the isolation-insulating layer 260 c is not formed.That is, the isolation space 260D may include a space surrounded by theisolation layer 264 between levels of a top surface of the base layer262 and a top surface of the isolation layer 264 and a space in theopening 262H. The plurality of isolation spaces 260D which are isolatedfrom each other may be formed to correspond to the plurality of pixelareas P1 and P2. That is, each of the plurality of isolation spaces 260Dmay be formed to correspond to each of the plurality of photoelectrictransducers 204.

The second width W2, which is the width of the opening 262H, may have asmaller value than that of the first width W1 of the stud layer 230. Thecoating layer 245 may not be exposed and the top surface thereof may becompletely covered due to the isolation-insulating layer 260 c with theopenings 262H. That is, the top surface of the coating layer 245 may betotally covered by the isolation-insulating layer 260 c so as to not beexposed at a bottom of the opening 262H. However, in some embodiments,when a misalignment occurs during the process of forming the secondphotoresist layer M2 of FIG. 3K, a portion of the coating layer 245 maybe exposed at the bottom of the opening 262H.

Referring to FIG. 3O, a lower transparent material layer 265 whichcovers a top of the isolation-insulating layer 260 c to fill theisolation space 260D is formed. The lower transparent material layer 265may be formed of, for example, ITO, IZO, ZnO, SnO₂, ATO, AZO, GZO, TiO₂,or FTO.

Referring to FIG. 3P, the lower transparent electrode layer 266 whichfills the isolation space 260D may be formed on the isolation-insulatinglayer 260 c by performing a planarization process on the lowertransparent material layer 265 in FIG. 3O until the isolation-insulatinglayer 260 c, that is, the isolation layer 264, is exposed. Theplanarization process for forming the lower transparent electrode layer266 may be performed by a CMP process.

The lower transparent electrode layer 266 may include the lower contact266C, which fills an inside of the opening 262H, and the lower electrode266E, which is connected with the lower contact 266C and disposed on thetop surface of the base layer 262.

That is, the lower transparent electrode layer 266 may be formed to fillthe isolation space 260D using a dual damascene method. Accordingly, thelower contact 266C and the lower electrode 266E may be integrallyformed. A top surface of the lower transparent electrode layer 266 and atopmost end of the isolation-insulating layer 260 c may have the samelevel. In particular, the top surface of the lower transparent electrodelayer 266 and a top end of the isolation layer 264 may have the samelevel. That is, the top surface of the lower transparent electrode layer266 and the top surface of the isolation layer 264 may form planes withthe same level (i.e., the top surfaces may be coplanar).

Due to the isolation layer 264, the lower transparent electrode layer266 may be separated to correspond to each of the first pixel area P1and the second pixel area P2. That is, a plurality of such separatedlower transparent electrode layers 266 may be formed to correspond tothe plurality of pixel areas P1 and P2. In detail, the lower contact266C and the lower electrode 266E, which form the lower transparentelectrode layer 266 filling a single isolation space 260D, may beintegrally formed.

When the coating layer 245 is not exposed at the bottom of the opening262H, the coating layer 245 may be spaced apart to not be in contactwith the lower transparent electrode layer 266. However, in someembodiments, when a misalignment occurs during the process of formingthe second photoresist layer M2 of FIG. 3K, a portion of the coatinglayer 245 may be in contact with the lower transparent electrode layer266.

Referring to FIG. 3Q, the organic photoelectric layer 272 is formed onthe lower transparent electrode layer 266. The organic photoelectriclayer 272 may be integrally formed on the plurality of lower transparentelectrode layers 266. The organic photoelectric layer 272 may be anorganic material which causes a photoelectric change only in light witha particular wavelength. For example, the organic photoelectric layer272 may cause the photoelectric change only at a wavelength of greenlight. For example, the organic photoelectric layer 272 may show amaximum absorption wavelength λmax from about 500 nm to about 600 nm inboth of the first and second pixel areas P1 and P2.

The organic photoelectric layer 272 may have, for example, a thicknessfrom about 1 nm to about 500 nm. In some embodiments, the organicphotoelectric layer 272 may have a thickness from about 5 nm to about300 nm. The organic photoelectric layer 272 may have a thickness capableof effectively improving photoelectric conversion efficiency byeffectively absorbing light and effectively separating and transferringpositive holes and electrons.

Referring to FIG. 3R, the upper transparent electrode layer 274 isformed on the organic photoelectric layer 272. The upper transparentelectrode layer 274 may be formed of, for example, ITO, IZO, ZnO, SnO₂,ATO, AZO, GZO, TiO₂, or FTO. The upper transparent electrode layer 274may be integrally (e.g., continuously) formed across the first pixelarea P1 and the second pixel area P2.

After that, as shown in FIG. 1, the micro lens 280 corresponding to thecolor filter layer 240 is formed on the upper transparent electrodelayer 274, thereby forming the image sensor 1. The micro lens 280 may beformed to overlap the corresponding color filter layer 240. A pluralityof such micro lenses 280 may be formed to correspond to respective onesof the plurality of color filter layers 240. The micro lens 280 maychange a path of light incident on areas except (other than) thephotoelectric transducer 204, and may concentrate the light on thephotoelectric transducer 204.

In some embodiments, the protective layer 278 may be further formedbetween the micro lens 280 and the upper transparent electrode layer274. The protective layer 278 may be formed of a transparent insulatingmaterial.

According to the method(s) of manufacturing the image sensor accordingto FIGS. 3A-3R, even when a misalignment occurs during the process offorming the second photoresist layer M2 in FIG. 3K, it is possible toprotect/prevent the coating layer 245 from being damaged, and thereby areliable image sensor may be formed.

FIGS. 4A to 4E are cross-sectional views illustrating a process ofmanufacturing the image sensor 1 of FIG. 1 according to some embodimentsof present inventive concepts. In the description of FIGS. 4A to 4E,content/descriptions duplicated with reference to FIGS. 1 and 3A to 3Rmay be omitted. In detail, FIGS. 4A to 4E are cross-sectional viewsillustrating a process after the operation(s) shown in FIG. 3G.

Referring to FIG. 4A, a first photoresist layer M1 a with a resist holeM1Ha which exposes a part of the preliminary insulating layer 260 isformed on the preliminary insulating layer 260. The resist hole M1Ha maybe disposed at a position corresponding to the opening 262H shown inFIG. 1.

Referring to FIG. 4B, with the first photoresist layer M1 a as anetching mask, a plurality of recessed portions 260R are formed byremoving a portion of the preliminary insulating layer 260. Theplurality of recessed portions 260R may be disposed at positionscorresponding to the openings 262H shown in FIG. 1.

The plurality of recessed portions 260R may be formed to not completelypass through the preliminary insulating layer 260.

Referring to FIG. 4C, the first photoresist layer M1 a in FIG. 4B isremoved. The first photoresist layer M1 a may be removed by an ashingprocess.

Referring to FIG. 4D, a second photoresist layer M2 a is formed on thepreliminary insulating layer 260. The second photoresist layer M2 a maybe formed at a position corresponding to the isolation layer 264 shownin FIG. 1.

Referring to FIG. 4E, with the second photoresist layer M2 a as anetching mask, the preliminary insulating layer 260 b with the protrudingportion 263 formed on/as a top thereof is formed by removing a portionfrom a top surface of the preliminary insulating layer 260 in FIG. 4D.The preliminary insulating layer 260 b may include the base portion 261,which covers the coating layer 245 and the stud layer 230, and theprotruding portion 263, which protrudes from the base portion 261.During a process of forming the protruding portion 263, the plurality ofrecessed portions 261R may increase in depth to be deeper than theplurality of recessed portions 260R shown in FIG. 4D.

After that, the second photoresist layer M2 a is removed, and therebythe result shown in FIG. 3M may be obtained. A plurality of recessedportions 261R may be formed to not completely pass through thepreliminary insulating layer 260 b. Accordingly, even when amisalignment occurs during a process of forming the first photoresistlayer M1 a in FIG. 4A, the coating layer 245 may not be exposed atbottoms of the plurality of recessed portions 261R.

After that, the image sensor 1 shown in FIG. 1 may be formed through theprocesses shown in FIGS. 3N to 3R.

FIGS. 5A to 5O are cross-sectional views illustrating a process ofmanufacturing an image sensor according to some embodiments of presentinventive concepts. In detail, FIGS. 5A to 5O are cross-sectional viewsillustrating the process of manufacturing the image sensor 2 shown inFIG. 2. In the description of FIGS. 5A to 5O, content/descriptionsduplicated with reference to FIGS. 2 and 3A to 3R may be omitted.

Referring to FIG. 5A, the semiconductor substrate 300 with the pluralityof pixel areas P1 and P2 defined by the device isolation layer 302 isprepared. A plurality of photoelectric transducers 304 and the pluralityof storage node areas 306 spaced apart from the plurality ofphotoelectric transducers 304 are formed in the plurality of pixel areasP1 and P2 of the semiconductor substrate 300, respectively.

The photoelectric transducers 304 may be disposed in the semiconductorsubstrate 300 to correspond to each of the first and second pixel areasP1 and P2. Each photoelectric transducer 304 may be a photodiode. Eachphotoelectric transducer 304 may include the first impurity area 304 aand the second impurity area 304 b. The first impurity area 304 a may beformed deeply from a top surface of the semiconductor substrate 300. Thesecond impurity area 304 b may be formed shallowly at the top surface ofthe semiconductor substrate 300. The first impurity area 304 a and thesecond impurity area 304 b may include different conductivity types. Forexample, the first impurity area 304 a may be doped with N-typeimpurities, and the second impurity area 304 b may be doped with P-typeimpurities.

The photoelectric transducer 304 may include pixels which sense redlight and blue light. For example, a pixel which senses red light may bein the first pixel area P1, and a pixel which senses blue light may bein the second pixel area P2. The storage node area 306 may be disposedin the semiconductor substrate 300 to correspond to each of the firstand second pixel areas P1 and P2 while being spaced apart from thephotoelectric transducer 304. The storage node area 306 may be, forexample, doped with N-type impurities. The storage node area 306 may beformed as a single doped area and may have a smaller area than that ofthe photoelectric transducer 304.

The interlayer dielectric structure 310 may be disposed on thesemiconductor substrate 300. The interlayer dielectric structure 310 mayinclude the plurality of interlayer dielectrics (e.g., dielectriclayers) 311, 312, 313, and 314 sequentially deposited on thesemiconductor substrate 300 and the etching stopper 316 disposed on atop surface of the plurality of interlayer dielectrics 311, 312, 313,and 314. In some embodiments, the interlayer dielectric 314 at a topmostend of the plurality of interlayer dielectrics 311, 312, 313, and 314may be formed thicker than the other interlayer dielectrics 311, 312,and 313. The plurality of interlayer dielectrics 311, 312, 313, and 314may be formed of oxides. For example, the plurality of interlayerdielectrics 311, 312, 313, and 314 may be formed of an HDP oxide film, aTEOS oxide film, TOSZ, SOG, USG, a low-k dielectric layer, etc. Theetching stopper 316 may be formed of a silicon nitride film or a siliconoxynitride film.

The wiring structure 320 is disposed in each of the first pixel area P1and the second pixel area P2 on the semiconductor substrate 300. Thewiring structure 320 may be formed of, for example, a metallic materialsuch as copper, aluminum, and tungsten. For example, the wiringstructure 320 may include the interlayer wires 321 disposed in at leasta portion of the plurality of interlayer dielectrics 311, 312, 313, and314 and the contact vias 323 which pass through the plurality ofinterlayer dielectrics 311, 312, 313, and 314 and connect the interlayerwires 321. The contact vias 323 may include the bottommost contact via323 a, the intermediate contact via 323 b, and the topmost contact via323 c. The bottommost contact via 323 a may be in contact with thestorage node area 306.

In some embodiments, the buffer via 325 may be provided between thebottommost contact via 323 a and the storage node area 306. The buffervia 325 may include, for example, carbon nanotubes. The buffer via 325may provide, for example, a material with a work function between ametal and silicon to reduce an energy barrier between the semiconductorsubstrate 300 and the wiring structure 320, thereby providing adequateohmic contact. For example, a work function of silicon may be 4.05 eV inthe semiconductor substrate 300, a work function of a metal (forexample, copper) may be 4.70 eV in the wiring structure 320, and a workfunction of the buffer via 325 (for example, carbon nanotubes) may befrom about 4.3 eV to about 4.8 eV. The buffer via 325 may reduce anenergy barrier between the silicon and the metal to allow electronsand/or positive holes to be better transferred to the storage node area306 through the wiring structure 320.

Referring to FIG. 5B, the stud layer 330 electrically connected with thecontact vias 323 is formed on the wiring structure 320. The stud layer330 may include the first stud layer 331 and the second stud layer 333formed on the first stud layer 331. The second stud layer 333 may beformed to surround side and top surfaces of the first stud layer 331,thereby having a larger width than that of the first stud layer 331. Thefirst stud layer 331 and the second stud layer 333 may be formed ofdifferent metallic materials. In some embodiments, the first stud layer331 may be formed of tungsten, and the second stud layer 333 may beformed of aluminum. The stud layer 330 may have the first width W1. Whenthe second stud layer 333 has a larger width than that of the first studlayer 331, the second stud layer 333 may have the first width W1.

Referring to FIG. 5C, the color filter layer 340 may be formed on thewiring structure 320. The color filter layer 340 may allow lightincident through the micro lens 380 to pass, thereby allowing only lightwith a necessary wavelength to be incident on the photoelectrictransducer 304. In some embodiments, an anti-reflection layer may beformed between the color filter layer 340 and the semiconductorsubstrate 300 to allow the light to be incident onto the photoelectrictransducer 304 by reducing/preventing the reflection of light. Theanti-reflection layer may be formed of, for example, SiON, SiC, SiCN,SiCO, etc.

The color filter layer 340 may include the first color filter layer 341and the second color filter layer 343. The first color filter layer 341and the second color filter layer 343 may be disposed in the pixel areaP1 and the second pixel area P2 to correspond to the photoelectrictransducers 304 formed therein, respectively. In some embodiments, thefirst color filter layer 341 disposed in the first pixel area P1 may bea red (R) color filter and the second color filter layer 343 disposed inthe second pixel area P2 may be a blue (B) color filter. Accordingly,the first pixel area P1 transmits light with a red wavelength to allowthe red wavelength to arrive at the photoelectric transducer 304. Also,the second pixel area P2 transmits light with a blue wavelength to allowthe blue wavelength to arrive at the photoelectric transducer 304.

The color filter layer 340 may be formed to have a top surface with alower level than that of the stud layer 330. That is, a height of thecolor filter layer 340 may be formed to have a smaller value than thatof the stud layer 330.

Referring to FIG. 5D, the coating layer 345 which covers the colorfilter layer 340 is formed. The coating layer 345 may be formed byforming a coating material layer which covers a top of the semiconductorsubstrate 300 on which the stud layer 330 and the color filter layer 340are formed and performing a planarization process. The coating layer 345may expose a top surface of the stud layer 330. The coating layer 345and the stud layer 330 may have top surfaces with the same level. Thatis, the top surfaces of the coating layer 345 and the stud layer 330 mayform planes with the same level (i.e., the surfaces may be coplanar).The coating layer 345 may be formed by forming the coating materiallayer and then partially removing the coating material layer until thetop surface of the stud layer 330 is exposed. The coating layer 345 maybe formed of a transparent organic material. In some embodiments, thecoating layer 345 may be formed of resin. The coating layer 345 may beon top of (e.g., may directly contact top surfaces of) the plurality ofcolor filter layers 340.

Referring to FIG. 5E, the preliminary insulating layer 360, which coversthe coating layer 345 and the stud layer 330, is formed. After that, thefirst photoresist layer M1 is formed on the preliminary insulating layer360. The first photoresist layer M1 may be formed at a positioncorresponding to the isolation layer 364 shown in FIG. 2.

Referring to FIG. 5F, with the first photoresist layer M1 as an etchingmask, a preliminary insulating layer 360 a with a protruding portion 363formed on a top thereof is formed by removing a part from a top surfaceof the preliminary insulating layer 360 in FIG. 5E. The preliminaryinsulating layer 360 a may include a base portion 361 which covers thecoating layer 345 and the stud layer 330 and the protruding portion 363which protrudes from the base portion 361.

Referring to FIG. 5G, the first photoresist layer M1 in FIG. 5F isremoved. The first photoresist layer M1 may be removed by an ashingprocess.

Referring to FIG. 5H, the second photoresist layer M2 with the resisthole M2H which exposes a part of the preliminary insulating layer 360 ahaving the protruding portion 363 is formed. The resist hole M2H may bedisposed at a position corresponding to the opening 362H shown in FIG.2. The second photoresist layer M2 may cover the entire protrudingportion 363.

Referring to FIG. 5I, with the second photoresist layer M2 as an etchingmask, a preliminary insulating layer 360 b having a plurality ofrecessed portions 361R is formed by removing a part of the preliminaryinsulating layer 360 a in FIG. 5H. The plurality of recessed portions361R may be disposed at positions corresponding to the openings 362Hshown in FIG. 2.

The plurality of recessed portions 361R may be formed to not completelypass through the preliminary insulating layer 360 b. Accordingly, evenwhen a misalignment occurs during a process of forming the secondphotoresist layer M2, the coating layer 345 may not be exposed atbottoms of the plurality of recessed portions 361R.

Referring to FIG. 5J, the second photoresist layer M2 in FIG. 5I isremoved. The second photoresist layer M2 may be removed by an ashingprocess.

The coating layer 345 may have properties similar to those of the secondphotoresist layer M2, for example, a property of being removed by theashing process. Accordingly, when the coating layer 345 is exposed atthe bottoms of the plurality of recessed portions 361R, at least a partof the coating layer 345 may be removed during a process of removing thesecond photoresist layer M2. However, since the plurality of recessedportions 361R may be formed to not completely pass through thepreliminary insulating layer 360 b in such a way that the coating layer345 is not exposed at the bottoms of the plurality of recessed portions361R, it is possible to protect/prevent at least a portion of thecoating layer 345 from being removed during the process of removing thesecond photoresist layer M2.

Referring to FIG. 5K, the isolation-insulating layer 360 c with aplurality of openings 362H is formed by partially removing a top of thepreliminary insulating layer 360 b in FIG. 5J having the plurality ofrecessed portions 361R in FIG. 5J and the protruding portion 363. Theplurality of openings 362H may be formed by removing the preliminaryinsulating layer 360 b from the bottoms of the plurality of recessedportions 361R. The plurality of openings 362H may pass through theisolation-insulating layer 360 c.

The isolation-insulating layer 360 c may be formed of, for example, anoxide. The isolation-insulating layer 360 c may include the base layer362 and the isolation layer 364 formed on the base layer 362. The baselayer 362 may have an opening 362H which exposes at least a portion ofthe stud layer 330. The isolation space 360D defined by theisolation-insulating layer 360 c, that is, the base layer 362 and theisolation layer 364, may be formed. A plurality of such isolation spaces360D may be formed to correspond to the plurality of pixel areas P1 andP2.

The isolation space 360D refers to a portion/region/area between abottom surface level and a top surface level of the isolation-insulatinglayer 360 c where the isolation-insulating layer 360 c is not formed.That is, the isolation space 360D may include a space surrounded by theisolation layer 364 between levels of a top surface of the base layer362 and a top surface of the isolation layer 364 and a space in theopening 362H. The plurality of isolation spaces 360D which are isolatedfrom each other may be formed to correspond to the plurality of pixelareas P1 and P2. That is, each of the plurality of isolation spaces 360Dmay be formed to correspond to each of the plurality of photoelectrictransducers 304.

The second width W2, which is the width of the opening 362H, may have asmaller value than that of the first width W1 of the stud layer 330. Thecoating layer 345 may not be exposed and a top surface thereof may becompletely covered due to the isolation-insulating layer 360 c havingthe opening 362H. That is, the top surface of the coating layer 345 maybe totally covered by the isolation-insulating layer 360 c so as not toexposed at a bottom of the opening 362H. However, in some embodiments,when a misalignment occurs during the process of forming the secondphotoresist layer M2 of FIG. 5H, a part of the coating layer 345 may beexposed at the bottom of the opening 362H.

Referring to FIG. 5L, a lower transparent material layer 365 whichcovers a top of the isolation-insulating layer 360 c to fill theisolation space 360D is formed. The lower transparent material layer 365may be formed of, for example, ITO, IZO, ZnO, SnO₂, ATO, AZO, GZO, TiO₂,or FTO.

Referring to FIG. 5M, the lower transparent electrode layer 366, whichfills the isolation space 360D, may be formed on theisolation-insulating layer 360 c by performing a planarization processon the lower transparent material layer 365 in FIG. 5L until theisolation-insulating layer 360 c, that is, the isolation layer 364, isexposed. The planarization process for forming the lower transparentelectrode layer 366 may be performed by a CMP process.

The lower transparent electrode layer 366 may include the lower contact366C, which fills an inside of the opening 362H, and the lower electrode366E, which is connected with the lower contact 366C and disposed on thetop surface of the base layer 362.

That is, the lower transparent electrode layer 366 may be formed to fillthe isolation space 360D using a dual damascene method. Accordingly, thelower contact 366C and the lower electrode 366E may be integrallyformed. A top surface of the lower transparent electrode layer 366 and atopmost end of the isolation-insulating layer 360 c may have the samelevel. In particular, the top surface of the lower transparent electrodelayer 366 and the top surface of the isolation layer 364 may have thesame level. That is, the top surface of the lower transparent electrodelayer 366 and the top surface of the isolation layer 364 may form planeswith the same level (i.e., the surfaces may be coplanar).

Due to the isolation layer 364, the lower transparent electrode layer366 may be separated to correspond to each of the first pixel area P1and the second pixel area P2. That is, a plurality of such separatedlower transparent electrode layers 366 may be formed to correspond tothe plurality of pixel areas P1 and P2. In detail, the lower contact366C and the lower electrode 366E, which form the lower transparentelectrode layer 366 filling a single isolation space 360D, may beintegrally formed.

When the coating layer 345 is not exposed at the bottom of the opening362H, the coating layer 345 may be spaced apart to not be in contactwith the lower transparent electrode layer 366. However, in someembodiments, when a misalignment occurs during the process of formingthe second photoresist layer M2 of FIG. 5H, a part of the coating layer345 may be in contact with the lower transparent electrode layer 366.

Referring to FIG. 5N, the organic photoelectric layer 372 is formed onthe lower transparent electrode layer 366. The organic photoelectriclayer 372 may be integrally formed on the plurality of lower transparentelectrode layers 366. The organic photoelectric layer 372 may be anorganic material which causes a photoelectric change only in light witha particular wavelength. For example, the organic photoelectric layer372 may cause the photoelectric change only at a wavelength of greenlight. For example, the organic photoelectric layer 372 may show amaximum absorption wavelength λmax from about 500 nm to about 600 nm inboth of the first and second pixel areas P1 and P2.

The organic photoelectric layer 372 may have, for example, a thicknessfrom about 1 nm to about 500 nm. In some embodiments, the organicphotoelectric layer 372 may have a thickness from about 5 nm to about300 nm. The organic photoelectric layer 372 may have a thickness capableof effectively improving photoelectric conversion efficiency byeffectively absorbing light and effectively separating and transferringpositive holes and electrons.

Referring to FIG. 5O, the upper transparent electrode layer 374 isformed on the organic photoelectric layer 372. The upper transparentelectrode layer 374 may be formed of, for example, ITO, IZO, ZnO, SnO₂,ATO, AZO, GZO, TiO₂, or FTO. The upper transparent electrode layer 374may be integrally formed across the first pixel area P1 and the secondpixel area P2.

After that, as shown in FIG. 2, the micro lens 380 corresponding to thecolor filter layer 340 is formed on the upper transparent electrodelayer 374, thereby forming the image sensor 2. The micro lens 380 may beformed to overlap the corresponding color filter layer 340. A pluralityof such micro lenses 380 may be formed to correspond to respective onesof the plurality of color filter layers 340. The micro lens 380 maychange a path of light incident on areas except (e.g., other than) thephotoelectric transducer 304, and may concentrate the light on thephotoelectric transducer 304.

In some embodiments, the protective layer 378 (illustrated in FIG. 2)may be further formed between the micro lens 380 and the uppertransparent electrode layer 374. The protective layer 378 may be formedof a transparent insulating material.

According to the method(s) of manufacturing the image sensor accordingto FIGS. 5A-5O, even when a misalignment occurs during the process offorming the second photoresist layer M2 in FIG. 5H, it is possible toprotect/prevent the coating layer 345 from being damaged, and thereby areliable image sensor may be formed.

FIGS. 6A to 6E are cross-sectional views illustrating a process ofmanufacturing an image sensor according to some embodiments of presentinventive concepts. In particular, FIGS. 6A to 6E are cross-sectionalviews illustrating the process of manufacturing the image sensor 2 shownin FIG. 2. In the description of FIGS. 6A to 6E, content/descriptionsduplicated with reference to FIGS. 2 and 5A to 5O may be omitted. Indetail, FIGS. 6A to 6E are cross-sectional views illustrating a processafter the processes shown in FIG. 5D.

Referring to FIG. 6A, the first photoresist layer M1 a with the resisthole M1Ha which exposes a part of the preliminary insulating layer 360is formed on the preliminary insulating layer 360. The resist hole M1Hamay be disposed at a position corresponding to the opening 362H shown inFIG. 2.

Referring to FIG. 6B, with the first photoresist layer M1 a as anetching mask, a plurality of recessed portions 360R are formed byremoving a portion of the preliminary insulating layer 360. Theplurality of recessed portions 361R may be disposed at positionscorresponding to the openings 362H shown in FIG. 2.

The plurality of recessed portions 360R may be formed to not completelypass through the preliminary insulating layer 360.

Referring to FIG. 6C, the first photoresist layer M1 a in FIG. 6B isremoved. The first photoresist layer M1 a may be removed by an ashingprocess.

Referring to FIG. 6D, the second photoresist layer M2 a is formed on thepreliminary insulating layer 360. The second photoresist layer M2 a maybe formed at a position corresponding to the isolation layer 364 shownin FIG. 2.

Referring to FIG. 6E, with the second photoresist layer M2 a as anetching mask, the preliminary insulating layer 360 b having theprotruding portion 363 formed on/as a top thereof is formed by partiallyremoving a top surface of the preliminary insulating layer 360 in FIG.6D. The preliminary insulating layer 360 b may include the base portion361, which covers the coating layer 345 and the stud layer 330, and theprotruding portion 363, which protrudes from the base portion 361.During a process of forming the protruding portion 363, the plurality ofrecessed portions 361R may increase in depth to be deeper than theplurality of recessed portions 360R shown in FIG. 6D.

After that, the second photoresist layer M2 a is removed, and therebythe result shown in FIG. 5K may be obtained. The plurality of recessedportions 361R may be formed to not completely pass through thepreliminary insulating layer 360 b. Accordingly, even if a misalignmentoccurs during the process of forming the first photoresist layer M1 a inFIG. 6A, the coating layer 345 may not be exposed at bottoms of theplurality of recessed portions 361R.

After that, the image sensor 2 shown in FIG. 2 may be formed through theprocesses shown in FIGS. 5L to 5O.

FIG. 7 is a cross-sectional view illustrating a main portion of an imagesensor 1 a according to some embodiments of present inventive concepts.In the description of FIG. 7, content/descriptions duplicated withreference to FIG. 1 may be omitted.

Referring to FIG. 7, in the image sensor 1 a, unlike the image sensor 1shown in FIG. 1, a portion of the coating layer 245 may be in contactwith the lower transparent electrode layer 266.

Like the image sensor 1 described with reference to FIGS. 3A to 4E, withthe image sensor 1 a according to some embodiments of present inventiveconcepts, even when a misalignment occurs during a process of forming aphotoresist layer used for forming the isolation-insulating layer 260 c,it is possible to protect/prevent the coating layer 245 from beingdamaged. For example, at least a portion of an oxide layer may remain ona portion of the coating layer 245 that would otherwise be exposed whena misalignment occurs when using the photoresist layer. (See, e.g.,FIGS. 3K-3M.)

FIG. 8 is a cross-sectional view illustrating a main portion of an imagesensor 2 a according to some embodiments of present inventive concepts.In the description of FIG. 8, content/descriptions duplicated withreference to FIG. 2 may be omitted.

Referring to FIG. 8, in the image sensor 2 a, unlike the image sensor 2shown in FIG. 2, a portion of the coating layer 345 may be in contactwith the lower transparent electrode layer 366.

Like the image sensor 2 described with reference to FIGS. 5A to 6E,according to the image sensor 2 a according to some embodiments ofpresent inventive concepts, even when a misalignment occurs during aprocess of forming a photoresist layer used for forming theisolation-insulating layer 360 c, it is possible to protect/prevent thecoating layer 345 from being damaged.

FIG. 9 is a cross-sectional view illustrating a readout circuit of animage sensor according to some embodiments of present inventiveconcepts. In detail, FIG. 9 illustrates the readout circuit whichincludes a green pixel and a red pixel of an image sensor according tosome embodiments of present inventive concepts.

Referring to FIG. 9, OPD and R_PD share a single floating diffusion areaFD. Also, in another example, OPD and B_PD share a single floatingdiffusion area FD. The floating diffusion area FD may be referred to asa floating diffusion node. When viewed from a pixel, a green pixel and ared pixel share a single floating diffusion area FD.

The readout circuit includes two transmission transistors TG1 and TG2,the floating diffusion area FD, a reset transistor RX, a drivetransistor DX, and a selection transistor SX.

A first transmission transistor TG1 operates in response to a firsttransmission control signal TS1. A second transmission transistor TG2operates in response to a second transmission control signal TS2. Thereset transistor RX operates in response to a reset control signal RS.The selection transistor SX operates in response to a selection signalSEL.

When an activation time of the first transmission control signal TS1 andan activation time of the second transmission control signal TS2 areappropriately controlled, a signal corresponding to electrical chargesgenerated by OPD and a signal corresponding to electrical chargesgenerated by R_PD may be transmitted to a column line COL according tooperations of the respective transistors DX and SX.

Here, OPD, R_PD, or B_PD may be embodied as a photo transistor, a photogate, a pinned photo diode (PPD), or a combination thereof.

FIG. 10 is a cross-sectional view illustrating a readout circuit of animage sensor according to some embodiments of present inventiveconcepts. In detail, FIG. 10 illustrates the readout circuit whichincludes a green pixel and a red pixel of an image sensor according tosome embodiments of present inventive concepts.

Referring to FIG. 10, a first readout circuit, which reads outelectrical charges generated by R_PD, and a second readout circuit,which reads out electrical charges generated by OPD, are mutuallyseparated. When viewed from a pixel, a green pixel and a red pixel aremutually separated.

The first readout circuit includes a first transmission transistor TGA,a first floating diffusion area FD1, a first reset transistor RX1, afirst drive transistor DX1, and a first selection transistor SX1.

The first transmission transistor TGA operates in response to a firsttransmission control signal TS1. The first reset transistor RX1 operatesin response to a first reset control signal RS1. The first selectiontransistor SX1 operates in response to a first selection signal SEL1.

The second readout circuit includes a second transmission transistorTGB, a second floating diffusion area FD2, a second reset transistorRX2, a second drive transistor DX2, and a second selection transistorSX2.

The second transmission transistor TGB operates in response to a secondtransmission control signal TS2. The second reset transistor RX2operates in response to a second reset control signal RS2. The secondselection transistor SX2 operates in response to a second selectionsignal SEL2.

When an activation time of the first transmission control signal TS1 andan activation time of the second transmission control signal TS2 areappropriately controlled, a signal corresponding to electric chargesgenerated by OPD and a signal corresponding to electrical chargesgenerated by R_PD may be transmitted to a column line COL according tooperations of the respective transistors DX1, SX1, DX2, and SX2.

FIG. 11 is a block diagram illustrating a configuration of an imagesensor 2100 according to some embodiments of present inventive concepts.

Referring to FIG. 11, the image sensor 2100 may include a pixel array2110, a controller 2130, a row driver 2120, and a pixel signal processor2140. The image sensor 2100 includes at least one of the image sensors1, 1 a, 2, and 2 a described with reference to FIGS. 1 to 8.

The pixel array 2110 may include a plurality of unit pixelstwo-dimensionally arranged. The unit pixel may include a photoelectrictransducer. The photoelectric transducer may generate charges byabsorbing light. An electrical signal (an output voltage) according tothe generated charges may be provided to the pixel signal processor 2140through a vertical signal line. The unit pixels included in the pixelarray 2110 may provide output voltages one at a time by row.Accordingly, the unit pixels in one row of the pixel array 2110 may beactivated at the same time by a selection signal output by the rowdriver 2120. The unit pixels in a selected row may provide outputvoltages according to absorbed light to an output line of acorresponding column.

The controller 2130 may control the row driver 2120 to allow the pixelarray 2110 to accumulate charges by absorbing light, to temporarilystore the accumulated charges, and to output an electrical signalaccording to the stored charges from the pixel array 2110 to the outside(e.g., external to the image sensor 2100). Also, the controller 2130 maycontrol the pixel signal processor 2140 to measure the output voltageprovided by the pixel array 2110.

The pixel signal processor 2140 may include a correlated double sampler(CDS) 2142, an analog-digital converter (ADC) 2144, and a buffer 2146.The CDS 2142 may sample and hold the output voltage provided by thepixel array 2110. The CDS 2142 may double sample a level of noise and alevel according to a generated output voltage, and may output a levelcorresponding to a difference therebetween. Also, the CDS 2142 mayreceive a ramp signal generated by a ramp signal generator 2148 andcompare the ramp signals, and thereby a comparison result may be output.

The ADC 2144 may convert an analog signal corresponding to the levelreceived from the CDS 2142 into a digital signal. The buffer 2146 maylatch the digital signal. The latched signal is sequentially output fromthe image sensor 2100 to the outside (e.g., external to the image sensor2100) to be transferred to an image processor.

FIG. 12 is a block diagram of a system 2200 including an image sensoraccording to some embodiments of present inventive concepts.

Referring to FIG. 12, the system 2200 may be one of various systemswhich need data, such as a computing system, a camera system, a scanner,a vehicular navigation system, a video phone, a security system, and amotion-detection system.

The system 2200 may include a central processing unit (CPU) (or aprocessor) 2210, a nonvolatile memory 2220, an image sensor 2230, aninput/output device 2240, and a random-access memory (RAM) 2250. The CPU2210 may communicate with the nonvolatile memory 2220, the image sensor2230, the input/output device 2240, and the RAM 2250 through a bus 2260.The image sensor 2230 may be provided as an independent semiconductorchip or may be integrated with the CPU 2210 to be provided as a singlesemiconductor chip. The image sensor 2230 includes at least one of theimage sensors 1, 1 a, 2, and 2 a described with reference to FIGS. 1 to8.

FIG. 13 illustrates an electronic system 3000 including an image sensor3040 and an interface according to some embodiments of present inventiveconcepts.

Referring to FIG. 13, the electronic system 3000 may be provided as adata processor capable of using or supporting a mobile industryprocessor interface (MIPI), for example, a mobile phone, a personaldigital assistant (PDA), a portable multimedia player (PMP), or a smartphone. The electronic system 3000 may include an application processor3010, the image sensor 3040, and a display 3050. The image sensor 3040includes at least one of the image sensors 1, 1 a, 2, and 2 a describedwith reference to FIGS. 1 to 8.

A camera serial interface (CSI) host 3012 provided in the applicationprocessor 3010 may serially communicate with a CSI device 3041 of theimage sensor 3040 via a CSI. Here, for example, an optical deserializer(DES) may be provided in the CSI host 3012, and an optical serializer(SER) may be provided in the CSI device 3041.

A display serial interface (DSI) host 3011 provided in the applicationprocessor 3010 may serially communicate with a DSI device 3051 of thedisplay 3050 via a DSI. Here, for example, an optical serializer may beprovided in the DSI host 3011, and an optical deserializer may beprovided in the DSI device 3051.

The electronic system 3000 may further include a radio frequency (RF)chip 3060 capable of communicating with the application processor 3010.A physical layer (PHY) 3013 of the electronic system 3000 and a PHY 3061of the RF chip 3060 may transmit and receive data according to a MIPIDigRF.

The electronic system 3000 may further include a global positioningsystem (GPS) 3020, a storage 3070, a microphone (MIC) 3080, a dynamicRAM (DRAM) 3085, and a speaker 3090. The electronic system 3000 maycommunicate using Wimax 3030, a wireless local area network (WLAN) 3100,ultra wideband (UWB) 3110, etc.

FIG. 14 is a perspective view schematically illustrating an electronicsystem to which an image sensor 4010 is applied according to someembodiments of present inventive concepts.

FIG. 14 illustrates an example of applying the electronic system 3000 toa mobile phone 4000. The mobile phone 4000 may include the image sensor4010. The image sensor 4010 includes at least one of the image sensors1, 1 a, 2, and 2 a described with reference to FIGS. 1 to 8.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true spirit and scope. Thus, to the maximum extent allowed by law,the scope is to be determined by the broadest permissible interpretationof the following claims and their equivalents, and shall not berestricted or limited by the foregoing detailed description.

What is claimed is:
 1. A method of forming an image sensor, the methodcomprising: forming an insulating layer on a color filter layer; etchingthe insulating layer to form an opening that at least partially exposesa metal structure that is adjacent a sidewall of the color filter layer;and forming a transparent electrode layer, wherein forming thetransparent electrode layer comprises simultaneously forming atransparent electrode material: in the opening of the insulating layer;and on a portion of the insulating layer that is outside of the opening.2. The method of claim 1, further comprising: before forming theinsulating layer, forming a transparent layer on the color filter layer.3. The method of claim 2, wherein forming the transparent electrodelayer comprises forming the transparent electrode layer to contact aportion of the transparent layer through the opening.
 4. The method ofclaim 2, wherein: forming the transparent layer on the color filterlayer comprises forming the transparent layer on a red first colorfilter layer and a blue second color filter layer; forming theinsulating layer comprises forming an oxide layer on the transparentlayer; and forming the transparent electrode layer comprises forming anindium tin oxide (ITO) layer on the oxide layer and on the metalstructure.
 5. The method of claim 1, further comprising: forming aphotoresist material on the insulating layer; and performing an etch ofthe insulating layer while the photoresist material is on the insulatinglayer.
 6. The method of claim 5, wherein: performing the etch of theinsulating layer while the photoresist material is on the insulatinglayer comprises performing a first etch of the insulating layer; themethod further comprises performing a second etch of the insulatinglayer to form a recess that overlaps the metal structure, withoutexposing the metal structure; and etching the insulating layer to formthe opening that at least partially exposes the metal structurecomprises performing a third etch of the insulating layer.
 7. The methodof claim 6, wherein: the photoresist material comprises a firstphotoresist layer; the method further comprises removing the firstphotoresist layer and forming a second photoresist layer on theinsulating layer, before performing the second etch of the insulatinglayer; and the method further comprises removing the second photoresistlayer, before performing the third etch that forms the opening that atleast partially exposes the metal structure.
 8. The method of claim 5,wherein: performing the etch comprises forming a protruding portion ofthe insulating layer; and forming the transparent electrode layercomprises forming the transparent electrode layer on the protrudingportion of the insulating layer.
 9. The method of claim 1, whereinforming the transparent electrode material comprises: depositing thetransparent electrode material on the insulating layer; and performing achemical mechanical polishing (CMP) process on the transparent electrodematerial until a protruding portion of the insulating layer is exposed.10. The method of claim 9, wherein the protruding portion of theinsulating layer that is exposed by the CMP process overlaps the colorfilter layer, and wherein the method further comprises forming anorganic photoelectric layer on the transparent electrode layer and onthe protruding portion of the insulating layer that is exposed by theCMP process.
 11. A method of forming an image sensor, the methodcomprising: forming a color filter layer on a semiconductor substrate;forming a transparent layer on the color filter layer; forming aninsulating layer on the transparent layer; etching the insulating layerto form an opening that exposes a portion of a metal structure that isadjacent a sidewall of the color filter layer; forming an electrodelayer on a first surface of the insulating layer, in the opening of asecond surface of the insulating layer that is opposite the firstsurface and closer than the first surface to the semiconductorsubstrate; and forming an organic photoelectric layer on the electrodelayer.
 12. The method of claim 11, further comprising: forming aphotoresist material on a portion of the insulating layer; andperforming an etch of the insulating layer while the photoresistmaterial is on the portion of the insulating layer, to form a protrudingportion of the insulating layer, wherein forming the electrode layercomprises forming the electrode layer on the protruding portion of theinsulating layer.
 13. The method of claim 11, wherein: forming thetransparent layer on the color filter layer comprises forming thetransparent layer on a red first color filter layer and a blue secondcolor filter layer; forming the insulating layer comprises forming anoxide layer on the transparent layer; and forming the electrode layercomprises forming an indium tin oxide (ITO) layer on the oxide layer.14. The method of claim 11, wherein the metal structure comprises atungsten portion and an aluminum portion on the tungsten portion, andwherein the forming the electrode layer comprises forming the electrodelayer to contact the aluminum portion.
 15. The method of claim 14,wherein sidewalls of the aluminum portion of the metal structure aretapered toward the electrode layer.
 16. A method of forming an imagesensor, the method comprising: forming an insulating layer on a colorfilter layer; forming a photoresist material on the insulating layer;etching the insulating layer to form a recess that overlaps a metalstructure that is adjacent a sidewall of the color filter layer whilethe photoresist material is on the insulating layer; removing thephotoresist material to expose a protruding portion of the insulatinglayer; and forming an electrode layer in an opening of the insulatinglayer that at least partially exposes the metal structure and on aportion of the insulating layer that is outside of the opening.
 17. Themethod of claim 16, further comprising performing a first etch of theinsulating layer; and then performing a second etch of the insulatinglayer to form the opening.
 18. The method of claim 17, wherein etchingthe insulating layer comprises performing a third etch of the insulatinglayer to form the recess that overlaps the metal structure, withoutexposing the metal structure, before performing the second etch of theinsulating layer.
 19. The method of claim 17, wherein forming theelectrode layer comprises forming the electrode layer on the protrudingportion of the insulating layer.
 20. The method of claim 19, wherein:the protruding portion of the insulating layer overlaps the color filterlayer; forming the electrode layer further comprises: depositing anelectrode material on the insulating layer; and performing a chemicalmechanical polishing (CMP) process on the electrode material until asurface of the protruding portion of the insulating layer is exposed;and the method further comprises forming an organic photoelectric layeron the electrode layer and on the surface of the protruding portion ofthe insulating layer that is exposed by the CMP process.